usb: dwc3-msm: Add support for charger detection

DWC3 OTG driver can detect charger detection using DWC3 core or
external charger detection circuitry. Add support for external
charger detector in DWC3 OTG driver for MSM platform. This module
detects DCD and SDP/CDP/DCP type of chargers.

Change-Id: I5d1aec183fbcdc9b03aac74d626a4c39c56ed3b7
Signed-off-by: Manu Gautam <mgautam@codeaurora.org>